Tag Archives: LiDAR

Multi-directional Hillshading

A hillshade is a shaded relief picture of the surface. Important for a hillshade is the position of the imaginary light source, which is taken into account for shading the image.

Normally, the direction of the light source is 315┬░ (north-west). Since the Service Update 20.5.3, it’s also possible to choose the option Multi-directional. It is a composite image made up of four images in which the light source comes from different directions. Like this, the terrain is more realistically represented, and overexposed and nonilluminated areas of the map are more balanced.

In OCAD, Hill Shading can be created from the DEM menu or from the DEM Import Wizard.

How to use OCAD and LiDAR to Calculate Climbing for Courses

In order to indicate the climbing for courses, many course setters invest a lot of time to manually add up the climbing along the optimal route. If a terrain model (DEM) is available, this can be done easier with OCAD. With the following workflow, which is also possible in the OCAD Course Setting Edition, the climbing can be calculated automatically to a certain extent:

  1. Start a course setting project, open a background map and draw a course.

2. In your course setting project, go to menu DEM > Open and open your terrain model (* _DTM.ocdDem). This file is generated during the LiDAR processing.

3. Now draw a line with the optimal route from start to finish. This has to be done for each course. Use any line symbol in the symbol box or create a new one.

4. Select one of these optimal routes and go to menu DEM > Create Profile. You will get a Total ascent value, which you can enter into Course Setting > Courses > Climb used.

In the Courses dialogue, there is also a Climb calculated value, which is just calculated automatically by adding the net ascent from each control to the next one. The value that is entered in Climb used will show up in the control description.

How to process large amounts of LiDAR data

LiDAR data are invaluable for mapping, as highly accurate contour lines and base maps can be created.

But when processing LiDAR data for larger areas, a computer can quickly become overloaded because not enough RAM is available and crashes.

To avoid this, you have to work with XML scripts for larger projects. This may seem complicated at first glance, but don’t worry: All you have to do is copy code and make some adjustments.

This is what you need to do:

  1. Download and unzip our folder structure in your chosen directory.
  2. Create a new OCAD File with the desired symbol set, map scale and georeferencing. The New Map Wizard can help you with that.
    Save this file as Template.ocd (means overwrite the Template.ocd file in the folder structure).
  3. Put your LiDAR files in the folder 0_LAZ.
  4. Open the XML_Script.xml file with a text editor and adjust the file pathes in the document.
  5. In the OCAD File menu, go to Execute XML Script and run the script.

The script imports LiDAR data and creates contour lines and a vegetation base map.
The single tiles are calculated separately and then cropped and merged together in the end.

The XML function for importing las/laz files and creating contour lines and vegetation map is also available in the OCAD Orienteering edition.

Find more about XML on our Wiki:
XML Script an LiDAR
XML Script in general

MapAnt Switzerland is Online

MapAnt Switzerland is an automatically generated orienteering map that should cover the whole of Switzerland in the near future. As a pilot project, the region of north-western Switzerland was calculated. To map all parts of Switzerland, we depend on free and freely available LiDAR data, which are not yet available in all cantons. However, this should be the case in near future.

The map tiles were created in OCAD. Contour lines and a vegetation map were derived from LiDAR data. Also, data from the official cadastral survey were imported and converted into OCAD symbols. Afterwards, WMTS tiles were exported and made available on the web with leaflet.

More about the MapAnt Switzerland project can be found in our Wiki.

Credits: MapAnt Switzerland was inspired by various similar projects worldwide and got financial support by OL G├Ânnerclub. Thanks a lot!